Integrated fan-out package and manufacturing method thereof

ABSTRACT

An integrated fan-out package includes a first and second dies, an encapsulant, and a redistribution structure. The first and second dies respectively has an active surface, a rear surface opposite to the active surface, and conductive posts on the active surface. The first and second dies are different types of dies. The active and rear surfaces of the first die are respectively leveled with the active and rear surfaces of the second die. Top surfaces of the conductive posts of the first and second dies are leveled. The conductive posts of the first and second dies are wrapped by same material. The encapsulant encapsulates sidewalls of the first and second dies. A first surface of the encapsulant is leveled with the active surfaces. The second surface of the encapsulant is leveled with the rear surfaces. The redistribution structure is disposed over the first die, the second die, and the encapsulant.

BACKGROUND

In recent years, the semiconductor industry has experienced rapid growthdue to continuous improvement in integration density of variouselectronic components, e.g. transistors, diodes, resistors, capacitors,etc. For the most part, this improvement in integration density has comefrom successive reductions in minimum feature size, which allows morecomponents to be integrated into a given area. Currently, integratedfan-out packages are becoming increasingly popular for theircompactness. In the integrated fan-out packages, planarization of themolding compound and formation of the redistribution circuit structureplays an important role during packaging process.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIGS. 1A-1N are schematic cross-sectional views illustrating variousstages of a method for manufacturing an integrated fan-out package inaccordance with some embodiments of the disclosure.

FIGS. 2A-2M are schematic cross-sectional views illustrating variousstages of a method for manufacturing an integrated fan-out package inaccordance with some alternative embodiments of the disclosure.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

Other features and processes may also be included. For example, testingstructures may be included to aid in the verification testing of the 3Dpackaging or 3DIC devices. The testing structures may include, forexample, test pads formed in a redistribution layer or on a substratethat allows the testing of the 3D packaging or 3DIC, the use of probesand/or probe cards, and the like. The verification testing may beperformed on intermediate structures as well as the final structure.Additionally, the structures and methods disclosed herein may be used inconjunction with testing methodologies that incorporate intermediateverification of known good dies to increase the yield and decreasecosts.

FIGS. 1A-1N are schematic cross-sectional views illustrating variousstages of a method for manufacturing an integrated fan-out package 10 inaccordance with some embodiments of the disclosure. Referring to FIG.1A, a first carrier 100 is provided. A de-bonding layer 110 and anadhesive layer 200 are sequentially formed on the first carrier 100. Insome embodiments, the first carrier 100 is a glass substrate. However,other material may be adapted as a material of the first carrier 100 aslong as the material is able to withstand the subsequent processes whilecarrying the package structure formed thereon. In some embodiments, thede-bonding layer 110 is a light-to-heat conversion (LTHC) release layerformed on the glass substrate. The LTHC release layer may serve thepurpose of de-bonding upon irradiation with for example, UV light. Insome embodiments, the adhesive layer 200 includes an elastic polymericmaterial or a layer made of elastic polymeric material. The elasticpolymeric material is, for example, phenol resin, epoxy resin, oracrylic polymer. In some embodiments, inorganic fillers such as silicondioxide (SiO₂) may be added into the elastic polymeric material. In someembodiments, the adhesive layer 200 may serve the function of a thermalrelease film or an UV release film. The thermal release film may bepeeled off when the film is heated to a specific temperature and the UVrelease film may be peeled off after UV exposure. In some embodiments,the adhesive layer 200 includes adhesion properties. In someembodiments, the adhesive layer 200 is able to accommodate conductiveposts of dies formed thereon subsequently and is able to well seal thesurfaces of the dies.

Referring to FIG. 1B, a plurality of first dies 300 and a plurality ofsecond dies 400 are provided. Each first die 300 has an active surface300 a, a rear surface 300 b opposite to the active surface 300 a, and aplurality of conductive posts 310 formed on the active surface 300 a.Each die 400 has an active surface 400 a, a rear surface 400 b oppositeto the active surface 400 a, and a plurality of conductive posts 410formed on the active surface 400 a. The conductive posts 310 of thefirst dies 300 and the conductive posts 410 of the second dies 400 mayinclude copper posts, for example. In some embodiments, the first dies300 may include the same types of chips and may be selected fromapplication-specific integrated circuit (“ASIC”) chips, analog chips,sensor chips, wireless and radio frequency chips, voltage regulatorchips or memory chips. In some embodiments, the second dies 400 mayinclude the same types of chips and may be selected fromapplication-specific integrated circuit (“ASIC”) chips, analog chips,sensor chips, wireless and radio frequency chips, voltage regulatorchips or memory chips. In certain embodiments, the first dies 300 andthe second dies 400 are different types of dies. For example, the firstdies 300 and the second dies 400 may encompass different types of chipsor different electronic components or elements. Depending on theapplication, the first dies 300 and the second dies 400 may performdifferent functions. In some embodiments, the first dies 300 may besystem on chip (SoC) dies and the second dies 400 may be high bandwidthmemory (HBM) dies. However, the disclosure is not limited thereto, andthe first dies 300 and the second dies 400 may be other types of diesbased on product needs. Since the first dies 300 and the second dies 400are different types of dies, the sizes and heights of the first andsecond dies 300, 400 would be different. For example, as illustrated inFIG. 1B, a height of the first dies 300 (as denoted by the sum of heightH₃₀₀ and height H₃₁₀) is different from a height of the second dies 400(as denoted by the sum of height H₄₀₀ and height H₄₁₀). It should benoted that throughout the disclosure, a height of an element is referredto the distance between the active surface and the rear surface of theelement in a thickness direction Z. In some embodiments, the height H₄₀₀is different from the height H₃₀₀. Moreover, the height H₃₁₀ of theconductive posts 310 of the first dies 300 may also be different fromthe height H₄₁₀ of the conductive posts 410 of the second dies 400. Itshould be noted that since the height H₃₁₀ and the height H₄₁₀ of theconductive posts 310, 410 are small compared to the height H₃₀₀ and theheight H₄₀₀ and may be negligible, for simplicity purposes in thedisclosure, the height H₃₁₀ is referred to as the height of the firstdie 300 and the height H₄₁₀ is referred to as the height of the seconddie 400.

The first dies 300 and the second dies 400 are placed on the adhesivelayer 200 such that the active surfaces 300 a, 400 a face the adhesivelayer 200. The first dies 300 and the second dies 400 are pressedagainst the adhesive layer 200. It should be noted that before pressing,the active surfaces 310 of the first dies 300 and the active surfaces410 of the second dies 400 are exposed. In other words, the first dies300 and the second dies 400 are bare dies without a dielectric layer(for example, a polybenzooxazole (PBO) layer) formed on the activesurfaces 310, 410 thereof. As such, as the first dies 300 and the seconddies 400 are pressed against the adhesive layer 200, the active surfaces310 of the first dies 300 and the active surfaces 410 of the second dies400 are in direct contact with a surface 200 a of the adhesive layer. Insome embodiments, a height H₂₀₀ of the adhesive layer 200 is at leastequal to or larger than the height H₃₁₀ of the conductive posts 310 ofthe first dies 300 and the height H₄₁₀ of the conductive posts 410 ofthe second dies 400. As such, as the first dies 300 and the second dies400 are pressed against the adhesive layer 200, the conductive posts 310of the first dies 300 and the conductive posts 410 of the second dies400 may be completely submerged into the adhesive layer 200. In otherwords, the conductive posts 310, 410 are encapsulated or well protectedby the adhesive layer 200.

As illustrated in FIG. 1B, due to the height differences in the firstdies 300 and the second dies 400, after the pressing process, the rearsurfaces 400 b of the second dies 400 are located at a level heighthigher than the rear surfaces 300 b of the first dies 300. It should benoted that two first dies 300 and two second dies 400 are respectivelyillustrated in FIG. 1B. However, in some alternative embodiments, thenumber of the first dies 300 and the second dies 400 may vary based onneed.

Referring to FIG. 1C, an encapsulation material 500 is formed over theadhesive layer 200. A first surface 500 a of the encapsulation material500 is in contact with the adhesive layer 200. In some embodiments, aheight H₅₀₀ of the encapsulation material 500 is larger than the heightH₃₁₀ of the first dies 300 and the height H₄₁₀ of the second dies 400.As such, the encapsulation material 500 completely encapsulates thefirst dies 300 and the second dies 400. In other words, a second surface500 b of the encapsulation material 500 is located at a level heighthigher than both of the rear surfaces 300 b of the first dies 300 andthe rear surfaces 400 b of the second dies 400. The first dies 300 andthe second dies 400 are not revealed and are well protected by theencapsulation material 500. In some embodiments, the encapsulationmaterial 500 may be a molding compound formed by a molding processes.However, in some alternative embodiments, the encapsulation material 500may be formed by an insulating material such as epoxy or other suitableresins. Meanwhile, the encapsulation material 500 may be formed throughother processes corresponding to the insulating material selected.

Referring to FIG. 1D, a thinning process is performed to reduce theheight H₅₀₀ of the encapsulation material 500, the height H₃₀₀ of thefirst dies 300, and the height H₄₀₀ of the second dies 400. In someembodiments, part of the encapsulation material 500 is removed to forman encapsulant 510 and to expose all of the first dies 300 and thesecond dies 400. In some embodiments, the thinning process includes amechanical grinding process, a chemical mechanical polishing (CMP)process, or a combination thereof. In some embodiments, the height H₅₀₀of the encapsulation material 500, the height H₃₀₀ of the first dies300, and the height H₄₀₀ of the second dies are reduced throughgrinding. In some embodiments, as mentioned above, the height H₃₀₀ ofthe first dies 300 is different from the height H₄₀₀ of the second dies400. When the encapsulation material 500 is partially removed to exposeone of the rear surfaces 300 b, 400 b, another one of the rear surfaces300 b, 400 b is still covered by the encapsulation material 500.Therefore, at least one of the rear surfaces 300 b, 400 b is furtherremoved until another rear surface 300 b, 400 b is exposed. In somealternative embodiments, after both of the rear surfaces 300 b, 400 bare exposed, the grinding process may be continued on the first dies300, the second dies 400, and the encapsulation material 500 to furtherreduce the overall thickness of the package formed later on.

As illustrate in FIG. 1D, the first surface 510 a of the encapsulant 510is leveled with the active surfaces 300 a of the first dies 300 and theactive surfaces 400 a of the second dies 400. The second surface 510 bof the encapsulant 510 is leveled with the rear surfaces 300 b of thefirst dies 300 and the rear surfaces 400 b of the second dies 400.Sidewalls SW₃₀₀ of the first dies 300 and sidewalls SW₄₀₀ of the seconddies 400 are encapsulated by the encapsulant 510. In some embodiments, aheight H510 of the encapsulant 510 is substantially equal to a heightH_(300′) of the thinned first dies 300 and a height H_(400′) of thethinned second dies 400.

Referring to FIG. 1E, a second carrier 600 having a de-bonding layer 610and a die attach film (DAF) 620 sequentially formed thereon is provided.In some embodiments, the second carrier 600 may be similar to the firstcarrier 100 and the de-bonding layer 610 may be similar to thede-bonding layer 110, so the detailed description thereof is omittedherein. The rear surfaces 300 b′ of the first dies 300 and the rearsurfaces 400 b′ of the second dies 400 are attached to the DAF 620.

Referring to FIG. 1E-1G, the first carrier 100 and the de-bonding layer110 are separated from the adhesive layer 200 and then removed. In someembodiments, the de-bonding layer 110 (e.g., the LTHC release layer) maybe irradiated by an UV laser such that the adhesive layer 200 is allowedto be peeled off from the first carrier 100. After the adhesive layer200 is separated from the first carrier 100, the structure is flippedupside down to render the structure illustrated in FIG. 1F.

Referring to FIG. 1G, the adhesive layer 200 is removed from the firstdies 300, the second dies 400, and the encapsulant 510 such that thefirst surface 510 a of the encapsulant 510, the active surfaces 300 a ofthe first dies 300, and the active surfaces 400 a of the second dies 400are exposed. In some embodiments, the adhesive layer 200 may be removedthrough a peel off process, a solvent wash off process, or an etchingprocess.

Referring to FIG. 1H, a base material layer 700 is formed on the firstsurface 510 a of the encapsulant 510, the active surfaces 300 a of thefirst dies 300, and the active surfaces 400 a of the second dies 400.The base material layer 700 has a first surface 700 a and a secondsurface 700 b opposite to the first surface 700 a. In some embodiments,the base material layer 700 is formed directly on the encapsulant 510covering the conductive posts 310, 410 of the first and second dies 300,400 such that the second surface 700 b of the base material layer 700 isin contact with the first surface 510 a of the encapsulant 510. The basematerial layer 700 has a height H₇₀₀ larger than the height H₃₁₀ of theconductive posts 310 of the first dies 300 and the height H₄₁₀ of theconductive posts 410 of the second dies 400. In other words, both of theconductive posts 310, 410 are encapsulated by the base material layer700. That is, both of the conductive posts 310, 410 are wrapped by asame material. In some embodiments, the base material layer 700 is madeof dielectric material. The dielectric material includes, for example,polyimide, epoxy resin, acrylic resin, phenol resin, benzocyclobutene(BCB), polybenzooxazole (PBO), or any other suitable polymer-baseddielectric material. In some embodiments, the base material layer 700may include fillers with a size smaller than a filler of conventionalmolding compound or encapsulant. In some alternative embodiments, thebase material layer 700 may be free of fillers. The base material layer700 may be formed through, for example, a coating process or alamination process. In some embodiments, the base material layer 700 maybe cured after coating.

Referring to FIG. 1I, the height H₇₀₀ of the base material layer 700,the height H₃₁₀ of the conductive posts 310 of the first dies 300, andthe height H₄₁₀ of the conductive posts 410 of the second dies 400 arereduced to form a base layer 710 and a plurality of conductive posts310′, 410′. Parts of the base material layer 700 and the conductiveposts 310, 410 may be removed through a fly cutting process or a CMPprocess. As illustrated in FIG. 1I, top surfaces 310 a′ of theconductive posts 310′ and top surfaces 410 b′ of the conductive posts410′ are exposed by the base layer 710. In some embodiments, a firstsurface 710 a of the base layer 710, the top surfaces 310 a′ of theconductive posts 310′, and top surfaces 410 b′ of the conductive posts410′ are leveled with each other. As such, a height H₇₁₀ of the baselayer 710, a height H₃₁₀ of the conductive posts 310, and a heightH_(410′) of the conductive posts 410 are substantially the same. In someembodiments, the heights H₃₁₀, H₄₁₀ of the conductive posts 310, 410 maybe approximately 30 μm. After grinding, the reduced heights H_(310′),H_(410′) may be approximately 7 μm.

As mentioned above, the first surface 510 a of the encapsulant 510 isleveled with the active surfaces 300 a of the first dies 300 and theactive surfaces 400 a of the second dies 400, so the base material layer700 is formed on a flat surface. Moreover, the conductive posts 310 ofthe first dies 300 and the conductive posts 410 of the second dies 400are formed on a same level height. Therefore, when reducing the heightsH₃₁₀, H₄₁₀ of the conductive posts 310, 410, the grinding process may beperformed easily to obtain a desired height in the thickness direction Zwith low under-grinding or over-grinding risk induced by heightvariation. Furthermore, as mentioned above, the base material layer 700includes fillers with small size or no filler. As such, after grinding,the first surface 710 a of the base layer 710 may be a smooth surfacewith little or no pits formed thereon.

Referring to FIG. 1J, a redistribution structure 800 is formed on thebase layer 710, the conductive posts 310′ of the first dies 300, and theconductive posts 410′ of the second dies 400. Thereafter, a plurality ofconductive terminals 900 are formed on the redistribution structure 800.In some embodiments, the redistribution structure 800 includes aplurality of redistribution conductive patterns 802 and a plurality ofdielectric layers 804 stacked alternately. The redistribution conductivepatterns 802 are interconnected with one another by conductive vias 806embedded in the dielectric layers 804. The redistribution conductivepatterns 802 are electrically connected to the conductive posts 310′ ofthe first dies 300 and the conductive posts 410′ of the second dies 400such that the redistribution structure 800 is electrically connected tothe first dies 300 and the second dies 400. In some embodiments, thematerial of the redistribution conductive patterns 802 includesaluminum, titanium, copper, nickel, tungsten, and/or alloys thereof. Theredistribution conductive patterns 802 may be formed by, for example,electroplating, deposition, and/or photolithography and etching. In someembodiments, the material of the dielectric layers 804 includespolyimide, epoxy resin, acrylic resin, phenol resin, benzocyclobutene(BCB), polybenzooxazole (PBO), or any other suitable polymer-baseddielectric material. The dielectric layer 804, for example, may beformed by suitable fabrication techniques such as spin-on coating,chemical vapor deposition (CVD), plasma-enhanced chemical vapordeposition (PECVD) or the like. In some embodiments, the material of thedielectric layers 804 in redistribution structure 800 is different fromthe material of the base layer 710. As mentioned above, the firstsurface 710 a of the base layer 710 may be a smooth surface with littleor no pits formed thereon. Therefore, in some embodiments, theredistribution structure 800 is formed on a smooth surface, which helpsto ease the process complexity while ensuring the reliability of theredistribution structure 800.

In some embodiments, the topmost redistribution conductive patterns 802are exposed from the topmost dielectric layer 804, and the exposedredistribution conductive patterns 802 includes under-ball metallurgy(UBM) patterns for ball mount. The conductive terminals 900 are formedon the UBM patterns. In some embodiments, the conductive terminals 900are attached to the UBM patterns through a solder flux (not shown). Insome embodiments, the conductive terminals 900 are, for example, solderballs, ball grid array (BGA) balls, or C4 bumps. In some embodiments,the conductive terminals 900 may be disposed on the UBM patterns by aball placement process and/or a reflow process.

Referring to FIG. 1K and FIG. 1L, the structure illustrated in FIG. 1Jis flipped upside down and is placed on a de-bonding carrier TP1. Thede-bonding carrier TP1 may include a frame and a tape being held tightlyby the frame. The tape of the de-bonding carrier TP1 helps to providesupport such that the second carrier 600 may be removed from the rearsurface 300 b′ of the first dies 300, the rear surface 400 b′ of thesecond dies 400, and the second surface 510 b of the encapsulant 510. Insome embodiments, the de-bonding layer 610 (e.g., the LTHC releaselayer) may be irradiated by an UV laser such that the DAF 620 is allowedto be peeled off from the second carrier 600. The DAF 620 is furtherremoved such that the rear surfaces 300 b′ of the first dies 300, therear surfaces 400 b′ of the second dies 400, and the second surface 510b of the encapsulant 510 are exposed, as illustrated in FIG. 1L. In someembodiments, the DAF 620 may be removed through a peel off process, asolvent wash off process, or an etching process.

Referring to FIG. 1M and FIG. 1N, after the second carrier 600 isremoved, the structure illustrated in FIG. 1L is separated from thede-bonding carrier TP1 and is flipped upside down again to attach to adicing carrier TP2. Similar to the de-boding carrier TP1, the dicingcarrier TP2 may also include a frame and a tape being held tightly bythe frame. The tape of the dicing carrier TP2 helps to provide supportsuch that the structure illustrated in FIG. 1M may be singulated to formthe integrated fan-out package 10 illustrated in FIG. 1N. In someembodiments, a cutting mechanism used for the singulation processinvolves dicing with a rotating blade or a laser beam. In other words,the dicing or singulation process is, for example, a laser cuttingprocess or a mechanical cutting process.

FIGS. 2A-2M are schematic cross-sectional views illustrating variousstages of a method for manufacturing an integrated fan-out package 20 inaccordance with some alternative embodiments of the disclosure. Varioussteps illustrated in FIGS. 2A-2M are similar to the steps illustrated inFIGS. 1A-1N, so similar elements are denoted by the same referencenumeral. Referring to FIGS. 2A-2B, the process is similar to the processillustrated in FIGS. 1A-1B, so the detailed description thereof isomitted herein. It should be noted that in some embodiments, theadhesive layer 200′ is formed of a thermosetting material. Thethermosetting material is, for example, DAF (die attach film), FOD (filmover die), FOW (film over wire), ABF (Ajinomoto Build-up Film),polyimide-based layers, or epoxy-based layers. In other words, theadhesive layer 200′ may be cured when energy (for example, heat orlight) is applied. In some embodiments, the adhesive layer 200′ includesadhesion properties. In some embodiments, the adhesive layer 200′ isable to accommodate conductive posts of dies formed thereon subsequentlyand is able to well seal the surfaces of the dies. In some embodiments,the adhesive layer 200′ includes fillers with smaller size as comparedto conventional encapsulant material or is free of fillers. Similar tothe step illustrated in FIG. 1B, a height H_(200′) of the adhesive layer200′ is equal to or larger than the height H₃₁₀ of the conductive posts310 of the first dies 300 and the height H₄₁₀ of the conductive posts410 of the second dies 400. As such, as the first dies 300 and thesecond dies 400 are pressed against the adhesive layer 200′, theconductive posts 310 of the first dies 300 and the conductive posts 410of the second dies 400 may be completely submerged into the adhesivelayer 200′.

Referring to FIG. 2C, after the first dies 300 and the second dies 400are pressed against the adhesive layer 200′, the adhesive layer 200′ iscured. As mentioned above, the adhesive layer 200′ includesthermosetting material. Therefore, upon irradiation of light withcertain wavelength or application of heat, the adhesive layer 200′ maybecured/hardened to encapsulate the conductive posts 310 of the first dies300 and the conductive posts 410 of the second dies 400. In other words,both of the conductive posts 310, 410 are wrapped by a same material.

Referring to FIGS. 2D-2G, the process is similar to the processillustrated in FIGS. 1C-1F, so the detailed description thereof isomitted herein. Referring to FIGS. 2G-2H, the height H_(200′) of theadhesive layer 200′, the height H₃₁₀ of the conductive posts 310 of thefirst dies 300, and the height H₄₁₀ of the conductive posts 410 of thesecond dies 400 are reduced to form an adhesive layer 210 and aplurality of conductive posts 310′, 410′. Parts of the adhesive layer200′ and the conductive posts 310, 410 may be removed through a flycutting process or a CMP process. As illustrated in FIG. 2H, topsurfaces 310 a′ of the conductive posts 310′ and top surfaces 410 b′ ofthe conductive posts 410′ are exposed by the adhesive layer 210. In someembodiments, a first surface 210 a of the adhesive layer 210 is attachedto the first surface 510 a of the encapsulant 510, the active surfaces300 a of the first dies 300, and the active surfaces 400 a of the seconddies 400. On the other hand, a second surface 210 b of the adhesivelayer 210, the top surfaces 310 a′ of the conductive posts 310′, and thetop surfaces 410 b′ of the conductive posts 410′ are leveled with eachother. As such, a height H₂₁₀ of the adhesive layer 210, a heightH_(310′) of the conductive posts 310, and a height H_(410′) of theconductive posts 410 are substantially the same. In some embodiments,the heights H₃₁₀, H₄₁₀ of the conductive posts 310, 410 may beapproximately 30 μm. After grinding, the reduced heights H_(310′),H_(410′) may be approximately 7 μm.

As mentioned above, the conductive posts 310 of the first dies 300 andthe conductive posts 410 of the second dies 400 are formed on a samelevel height. Therefore, when reducing the heights H₃₁₀, H₄₁₀ of theconductive posts 310, 410, the grinding process may be performed easilyto obtain a desired height in the thickness direction Z with lowunder-grinding or over-grinding risk induced by height variation. Asmentioned above, the adhesive layer 200′ includes fillers with smallsize or no filler. As such, after grinding, the second surface 210 b ofthe adhesive layer 210 may be a smooth surface with little or no pitsformed thereon.

Referring to FIG. 2I, a redistribution structure 800 is formed on theadhesive layer 210, the conductive posts 310′ of the first dies 300, andthe conductive posts 410′ of the second dies 400. Thereafter, aplurality of conductive terminals 900 are formed on the redistributionstructure 800. The redistribution structure 800 and the conductiveterminals 900 of FIG. 2I are similar to the redistribution structure 800and the conductive terminals 900 of FIG. 1J, so the detaileddescriptions thereof are omitted herein. In some embodiments, thematerial of the dielectric layers 804 in redistribution structure 800 isdifferent from the material of the adhesive layer 210. As mentionedabove, the second surface 210 b of the adhesive layer 210 may be asmooth surface with little or no pits formed thereon. Therefore, in someembodiments, the redistribution structure 800 is formed on a smoothsurface, which helps to ease the process complexity while ensuring thereliability of the redistribution structure 800.

Referring to FIGS. 2J-2M, the process is similar to the processillustrated in FIGS. 1K-1N to obtain the integrated fan-out package 20,so the detailed description thereof is omitted herein.

In accordance with some embodiments of the disclosure, an integratedfan-out package includes a first die, a second die, an encapsulant, anda redistribution structure. The first die and the second dierespectively has an active surface, a rear surface opposite to theactive surface, and a plurality of conductive posts formed on the activesurface. The first die and the second die are different types of dies.The active surface of the first die is leveled with the active surfaceof the second die. The rear surface of the first die is leveled with therear surface of the second die. A top surface of the conductive posts ofthe first die is leveled with a top surface of the conductive posts ofthe second die. The conductive posts of the first die and the conductiveposts of the second die are wrapped by a layer of a same material. Theencapsulant encapsulates sidewalls of the first die and sidewall of thesecond die. The encapsulant has a first surface and a second surfaceopposite to the first surface. The first surface is leveled with theactive surfaces of the first die and the second die. The second surfaceis leveled with the rear surface of the first die and the second die.The redistribution structure is over the first die, the second die, andthe encapsulant. The redistribution structure is electrically connectedto the first die and the second die.

In accordance with some embodiments of the disclosure, a manufacturingmethod of an integrated fan-out package includes at least the followingsteps. A carrier having an adhesive layer formed thereon is provided. Afirst die and a second die are provided on the adhesive layer. A heightof the first die is different from a height of the second die. The firstdie has first conductive posts and the second die has second conductiveposts. The first die and a second die are pressed against the adhesivelayer to make the active surfaces of the first die and the second die bein direct contact with the adhesive layer and the first and secondconductive posts be submerged into the adhesive layer. The adhesivelayer is cured. An encapsulant is formed to encapsulate the first dieand the second die. The carried is removed from the adhesive layer.Heights of the adhesive layer and the first and second conductive postsare reduced such that the first and second conductive posts are exposedfrom the adhesive layer. A redistribution structure is formed over theadhesive layer and the first and second conductive posts such that theredistribution structure is electrically connected to the first andsecond conductive posts.

In accordance with some alternative embodiments of the disclosure, amanufacturing method of an integrated fan-out package includes at leastthe following steps. A first carrier having an adhesive layer formedthereon is provided. A first die and a second die are pressed againstthe adhesive layer. The first die and the second die respectively has anactive surface, a rear surface opposite to the active surface, and aplurality of conductive posts formed on the active surface. A height ofthe first die is different from a height of the second die. The activesurfaces of the first die and the second die are pressed to be in directcontact with the adhesive layer. The conductive posts are pressed to besubmerged into the adhesive layer. An encapsulant is formed toencapsulate the first die and the second die. The rear surfaces of thefirst die and the second die are attached to a second carrier. The firstcarrier is removed. The adhesive layer is removed from the first die,the second die, and the encaspulant. A base material layer is formedover the active surface of the first die and the second die toencapsulate the conductive posts. Heights of the base material layer andthe conductive posts are reduced. A redistribution structure is formedover the conductive posts such that the redistribution structure iselectrically connected to the conductive posts. The second carrier isremoved from the rear surfaces of the first die and the second die.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A manufacturing method of an integrated fan-outpackage, comprising: providing a first carrier having an adhesive layerformed thereon; pressing a first die and a second die against theadhesive layer, wherein the first die and the second die respectivelyhas an active surface, a rear surface opposite to the active surface,and a plurality of conductive posts formed on the active surface, aheight of the first die is different from a height of the second die,wherein the active surfaces of the first die and the second die arepressed to be in direct contact with the adhesive layer, and theplurality of conductive posts are submerged into the adhesive layer;forming an encapsulant to encapsulate the first die and the second die;attaching the rear surfaces of the first die and the second die to asecond carrier; removing the first carrier and removing the adhesivelayer from the first die, the second die, and the encaspulant; forming abase material layer over the encapsulant and the active surfaces of thefirst die and the second die to encapsulate the conductive posts;reducing heights of the base material layer and the plurality ofconductive posts; forming a redistribution structure over the pluralityof conductive posts such that the redistribution structure iselectrically connected to the plurality of conductive posts; andremoving the second carrier from the rear surfaces of the first die andthe second die.
 2. The method according to claim 1, further comprising asingulation process to singulate the integrated fan-out packages.
 3. Themethod according to claim 1, further comprising forming a plurality ofconductive terminals over the redistribution structure.
 4. The methodaccording to claim 1, wherein the adhesive layer is formed of an elasticpolymeric material.
 5. The method according to claim 1, wherein a heightof the adhesive layer is larger than or equal to a height of theplurality of conductive posts of the first die and a height of theplurality of conductive posts of the second die.
 6. The method accordingto claim 1, wherein removing the adhesive layer comprises applying apeel off process, a solvent wash off process, or an etching process. 7.The method according to claim 1, wherein reducing heights of the basematerial layer and the plurality of conductive posts comprisesperforming a fly cutting process or a chemical mechanical polishingprocess.
 8. The method according to claim 1, wherein forming theencapsulant comprises: forming an encapsulation material over theadhesive layer to encapsulate the first die and the second die, whereina height of the encapsulation material is larger than the height of thefirst die and the height of the second die; and reducing the heights ofthe encapsulation material, the first die, and the second die to formthe encapsulant, wherein a surface of the encapsulant is leveled withthe rear surfaces of the first die and the second die.
 9. Amanufacturing method of an integrated fan-out package, comprising:providing a carrier having an adhesive layer formed thereon; providing afirst die and a second die on the adhesive layer, wherein a height ofthe first die is different from a height of the second die, the firstdie has first conductive posts and the second die has second conductiveposts, the first conductive posts have substantially a same height, andthe second conductive posts have substantially a same height; pressingthe first die and the second die against the adhesive layer to make theactive surfaces of the first die and the second die be in direct contactwith the adhesive layer and the first and second conductive posts besubmerged into the adhesive layer; forming an encapsulant to encapsulatethe first die and the second die; removing the carrier from the adhesivelayer; removing at least a portion of the adhesive layer; reducingheights of the first and second conductive posts such that top surfacesof the first conductive posts are leveled with top surfaces of thesecond conductive posts, wherein the first and second conductive postsare wrapped by a layer of a same material; and forming a redistributionstructure over the first and second conductive posts such that theredistribution structure is electrically connected to the first andsecond conductive posts.
 10. The method according to claim 9, furthercomprising a singulation process to singulate the integrated fan-outpackages.
 11. The method according to claim 9, further comprisingforming a plurality of conductive terminals over the redistributionstructure.
 12. The method according to claim 9, wherein the adhesivelayer is formed of an elastic polymeric material.
 13. The methodaccording to claim 9, wherein the first die and the second die aredifferent types of dies.